ScienceNOW:
If efficiency were all that matters, animals would hobble
around like pirates with two peg legs. That's because,
mathematically speaking, running with stiff legs requires less
energy. But humans and many other animals have "squishy" legs,
and a new simulation suggests why. When attached to real,
floppy bodies, so-called compliant legs prove more efficient,
absorbing more force and offering more stability in rough
terrain. The finding helps explain the long-puzzling paradox of
why animals crouch and bounce as they run and may change how
researchers model animal locomotion.
